matplotlib plt.text（）的具体用法——画图时给图中的点加标签

plt.text(x, y, s, fontsize, verticalalignment,horizontalalignment,rotation , **kwargs)

import pandas as pd #导入数据分析模块
import matplotlib.pyplot as plt #导入绘图模块类
plt.rcParams['font.sans-serif']=['SimHei'] #图中文字体设置为黑体
plt.rcParams['axes.unicode_minus']=False #负值显示
data=pd.read_excel(r"D:\城市租赁地图\人流流动与疫情发展\百度迁徙.xlsx") #读取数据
city_name=data['city'] #城市名称
people_flow=data['out_people']*100 #流出人口,单位百人
confirm=data['confirm(2.10)'] #确诊人数

fig=plt.figure(figsize=(8,6)) #新建画布
ax=plt.subplot(1,1,1) #子图初始化
ax.scatter(people_flow,confirm) #绘制散点图   
ax.set_title("人口流入-确诊人数")
ax.set_xlabel("人口流入数（百人）")
ax.set_ylabel("确诊人数")
plt.show()

ax.text(430, 337, "北京", fontsize=12, color = "r", style = "italic", weight = "light", verticalalignment='center', horizontalalignment='right', rotation=90)

for i in range(len(confirm)):
    ax.text(people_flow[i]*1.01, confirm[i]*1.01, city_name[i], fontsize=10, color = "r", style = "italic", weight = "light", verticalalignment='center', horizontalalignment='right',rotation=0) #给散点加标签

# -*- coding: utf-8 -*-
"""
Created on Sat Feb 15 10:29:38 2020
project name:add_annotation
@author: 帅帅de三叔
"""
import pandas as pd #导入数据分析模块
import matplotlib.pyplot as plt #导入绘图模块类
plt.rcParams['font.sans-serif']=['SimHei'] #图中文字体设置为黑体
plt.rcParams['axes.unicode_minus']=False #负值显示
data=pd.read_excel(r"D:\城市租赁地图\人流流动与疫情发展\百度迁徙.xlsx") #读取数据
city_name=data['city'] #城市名称
people_flow=data['out_people']*100 #流出人口,单位百人
confirm=data['confirm(2.10)'] #确诊人数

fig=plt.figure(figsize=(8,6)) #新建画布
ax=plt.subplot(1,1,1) #子图初始化
ax.scatter(people_flow,confirm) #绘制散点图   
ax.set_title("人口流入-确诊人数")
ax.set_xlabel("人口流入数（百人）")
ax.set_ylabel("确诊人数")
#ax.text(430, 337, "北京", fontsize=12, color = "r", style = "italic", weight = "light", verticalalignment='center', horizontalalignment='right',rotation=90)
for i in range(len(confirm)):
    ax.text(people_flow[i]*1.01, confirm[i]*1.01, city_name[i], 
            fontsize=10, color = "r", style = "italic", weight = "light",
            verticalalignment='center', horizontalalignment='right',rotation=0) #给散点加标签
plt.show()